Sophia Electric Aqua 274B Rectifier Tube
2021 Positive Feedback Writers’ Choice Award: "I've already given a well-deserved Writers' Choice Award to Sophia Electric for their Aqua 274B rectifiers in 2017. Nothing has changed since then, and the Aqua 274B rectifiers are still my all-time favorite rectifiers for their superbly balanced combination of clarity, resolving power, and naturalness that they share with the Sophia Electric 45 mesh plates. I should add that the Aqua 274B rectifiers from that 2017 review are still going strong four years later, and are still sounding as fantastic as they did when I first received them. " -- Jeff Day
Jeff Day's Positive Feedback Online Review: The Art of Vacuum Tubes: Sophia Electric 45 Mesh Plate Triodes and Aqua 274B Rectifier
"The Sophia Electric Aqua 274B rectifiers remain my all-time favorite rectifiers for that same combination of clarity, resolving power, and naturalness that they share with the Sophia Electric 45 mesh plates. If you have an amplifier that will accept a 274B rectifier, I've found the Sophia Electric Aqua 274B rectifier an easy path to better performance." -- Jeff Day
Jeff Day's Positive Feedback Online Review: “The sonics with Sophia Electric Aqua 274B rectifiers were superb, with a huge sense of space, vividly present images, a wide and deep soundstage, lots of resolution of musically meaningful nuance, and superb dynamics.
"The Sophia Electric Aqua 274B rectifiers easily outperformed my British NOS Haltron 5U4G rectifiers and the also excellent NOS RCA 5U4GB rectifiers, making them sound lean, washed out tonally, bleached in tone color, and rather average, which they aren't!
"The Sophia Electric Aqua 274B rectifiers are just so good that my other rectifiers paled in comparison, with Aqua 274B's being transparent, nuanced, smooth, colorful, natural, and dynamic presentation, that makes the music sound live, beautiful, and emotionally involving—they're something special!" -- Jeff Day
Sophia Electric Princess mesh plate 274B and rigid plate 274B tubes have been widely praised as the best sounding rectifier tubes ever made. However there is a catch - the first capacitor after the rectifier tube needs to be small. The max value allowed for the Princess 274B mesh plate is 4uf, or 8uf for the Princess 274B rigid plate. But for a typical 300B single ended amplifier, it is usually larger than 8uf. To overcome this limitation, Sophia Electric came out with a newly designed Aqua 274B rectifier tube to raise the limitation from 8uf to 47uf. This Aqua 274B can directly replace 5U4G in most amplifiers with great sonic improvement.
Aqua and WE 274B tubes would deliver 150ma-160ma of current at 430vDC per 274B tube.
Stereo 300B tube amplifier needs to have one 274B rectifier tube per channel, two 274B rectifier tubes for two channels. If the amp was designed to have only one rectifier tube for both channels, then 5U4G is more suitable.
Option 1: $240 per tube with one year warranty
Option 2: $199.99 per tube with 30 days warranty